Automatic bicycle transmission



June.17, 1952 w. e. SPENCER 2,600,586

I AUTOMATIC BICYCLE TRANSMISSION Filed April 16, 1949 4 Sheets-Sheet 1Gttorneg June. 1952 w. G. SPENCER 2,600,586

AUTOMATIC BICYCLE TRANSMISSION Filed April 16 1849 4 Sheets-Sheet 2 24.Smaentor Mum/v6. Spa-N052 June 17, 1952 w. e. SPENCER AUTOMATIC BICYCLETRANSMISSION 4 Sheets-Sheet 3 Filed April 16, 1949 3nnentor, MLL/AIM5PE/YCE2 Gttorneg June 17, 1952 w. e. SPENCER 2,600,586

AUTOMATIC BICYCLE TRANSMISSION Filed April 16, 1949 4 Sheets-Sheet 43nnentor, ML L/AM 65 5PE/Y6EQ Gttorneg Patented June 17, 1952 UNITEDSTATES PATENT *OFIFICE. f

AUTOMATIC BICYCLE TRANSMISSION William G. Spencer, Burbank, Calif.

Application April 16, 1949, Serial No. 87,979

7 Claims. (01. 74-751) The present invention relates to an automatictransmission for use on power or manual driven mechanisms generally, andparticularly, on bicycles.

An object of the invention is the provision of a device which may besubstituted for the ordinary crank shaft of a bicycle without entailingchange in the crank hanger box. Generally, the crank shaft carries aspocket wheel between which and 'a small sprocket carried by the rearwheel of the bicycle, a continuous chain is passed. The presentinvention is in compact form and is substituted for the crank shaft.

A further object of the invention is the provision of a bicycletransmission the ratio of which is changed by the rider of the bicyclethrough the simple expedient of applying a sudden thrust force againstthe pedals. By way of example, if it becomes necessary to rapidlyrevolve the driving crank while the rear wheel is propelled at a slowerspeed of revolution, the transmission gearing is shifted. Theconstruction of the invention is such that the transmission will not ofnecessity shift during ordinary pedaling, whether the pedaling be foruphill, or on level surface. The construction of the transmissionrequires an impact or increase of torque upon the pedals to causeshifting from high to low gear.

A further object of the invention is the provision of a transmissionwhich does not require any external control for effecting a change inspeed, such as ordinarily practiced in motorcycle or bicycletransmissions. The inventor is aware that prior investigators in thisart have provided change speed mechanism consisting of a plurality ofgears adapted to intermesh, with certain of the gears adapted to beshifted to provide for change in speed; but in every instance, so far asthe inventor is aware, such mechanism has required the use of linkageand a hand operated lever to effect a shifting of the gears.

A further object of the invention is the provision of a bicycletransmission which is simple of construction, inexpensive in cost ofmanufacture, easily repaired, does not require an expert to install thesame in a bicycle, which may be standardized for bicycles of differentmakes, and which is superior to devices for effecting a change in speedin bicycles now known to the inventor.

With the above-mentioned and other objects in view, the inventionconsists in the novel and useful provision, formation, construction,association, and relative arrangement of parts, members 2 and features,all as shown in one embodiment in the accompanying drawings, describedgener-'- ally and more particularly pointed out in the claims.

In the drawings,

Figure 1 is a fragmentary perspective View of the device of theinvention shown incorporated within the driving sprocket hanger box of abicycle;

Figure 2 is an enlarged fragmentary sectional view on the line 2-2 ofFigure 1, the mechanism being in what is known as high gearrelationship;

Figure 3 is a sectional view on the line 3- -3 of Figure 2;

Figure 4 is a sectional view on line 4-4 of Figure 2;

Figure 5 is a sectional view on line 5-5 of Figure 2;

Figure 6 isa sectional view on line 6-6 of Figure 2;

Figure 7 is a sectional view similar to Figure 3, certain of the partsbeing in moved relationship and in the act of shifting to low gear;

Figure 8 is a view similar to Figure 4 with parts in moved relationship,and in the act of shift ing to low gear;

Figure 9 is a cross sectional view similar to Figure 5, the partsbeingin moved relationship;

Figure 10 is a sectional view similar to Figure 6, the parts being inmoved relationship;

Figure 11 is an assembled perspective view of parts of the inventionwhich are normally confined within-a casing, the said figure showing thedrive gear, the shifting gear segment, and associated mechanism foractuating the said gear segment to maintain either a high gear, or a lowgear drive;

Figure 12 is a separated perspective view of parts which cooperate withthe mechanism of Figure 11;

Figure 13 is a separated perspective view of the cam release assembly;

Figure 14 is a separated perspective view of the shifting gear assembly;and

Figure 15 is a perspective view of an eccentric sleeve shaft used in thepractice of the invention.

Referring now with particularity to the drawings, the improved bicycletransmission is designated as an entirety by l, and the 'same is adaptedto be carried within the crank box 2. The box ordinarily axiallyconfines a shaft upon which is mounted a sprocket wheel and a pair ofcranks provided with pedals. The sprocket wheel drives a continuouschain, the chain in turn driving a small sprocket secured to the rearbicycle wheel. In practicing the present invention, I remove theordinary shaft with its bearings and cups from the crank box 2 andinsert within the box the transmission of the present invention.

The function of the transmission of the inventionis to proyidea change.gear ratio so that the bicycle rider may climb a hillwith ease, or pedalin the normal manner when on a level course.

The present invention differs from ordinary transmissions for bicycleswhich includeagear shift mechanism operated by the rider upon handactuation of a lever and cable or linkage placed adjacent the handlebars or atsome location on the bicycle frame. The present inventionaffords a shifting by actuation of the cranks so that during apedalingoperation control of gear shifting is through the cranks, the handsat-all times remaining free for steering the bicycle.

My completed transmission comes in what may be termed a cartridge inthat it is fully assembled and ready for insertion within the crank box2, after which the cranks are secured to the shaft, and the device isready for operation.

Referring to Figure l, the transmission includes a shaft 3, to which aresecured cranks 4 and, 5 carrying the usual pedals designated generallyas 6. The driving sprocket 1, Figure 2; is not secured directly to theshaft 3, as is ordinary practice, but is secured to means 8 w comprisinga sleeve by means 9 which consists of a nut having screw engagement withone end of the means, 8 andv a fixed engagement with the sprocket. Thesleeve of the means 8 hasa flared end portion In to provide a bearingrace H, and the said sleeve is internally providedwith longitudinallyextending gear teeth l2 -which will be designated hereinafter as theinternal drive gear. tointernal bore diameter at I3.

The shaft 3 is passed through what is termed the eccentric sleeve shafti l (see. Figure The eccentric sleeve shaft has co-axial bores at l5, l6and l! which are eccentric to the axis of the sleeve shaft I4 and as-aconsequence, the shaft 3 whichis passed through the bores I5, l6 and I1is eccentric to the axis'of the sleeve shaft M. The eccentric sleeveshaft [4 is semi-cylindrically cut away at two spaced zones and theshaft M at said zones is provided with eccentric semi-circularconcavities i8 and IS. The shaft I4 has a reduced diameter end at whichis externally screw threaded at 2|. The opposite end 22 is externallyscrew threaded and provided with a longitudinal bore 23, as shown inFigure 2. This bore is exposed in the form of a groove in theconcavities l8 and I9, as shown in Figures 2 and'15. Thisconstructionpermits a key 24 to pass through the bore at one end of thesleeve shaft, as shown in Figure 2. This key acts as a stop for elementsof the invention to be described.

A gear 25 is splined or otherwise secured to the. shaft 3, the said gearbeing positioned withinthe concavity l8. The gear is adapted assembly(Figure 14) is' confined within; the- Thissleeve is enlarged asconcavity l8 adjacent gear 25, and sleeve portion 26. The shifting gearassembly is illusprovided with a segment of teeth 33 The enlargementcarries a stop portion at 34 (see Figure 8). The shifting gear segmenthas a pitch diameter equal to the pitch diameter of gear teeth l2 andhas its hub located eccentric to the center of its pitch diameter. Allteeth, on gear'segment 3|), save one, are shaved in a mannerto reducethe addendum of each succeeding tooth sothat the radii from the hub tothe extremities of all teeth on the segment are equal to the radii fromthe center of shaft 3 to the extremitiesof the teeth of pinion gear 25.

Asshown ,in-FigureB, the external diameter of the sleeve is on aconstant radius from one of the teeth 33 to the stop 34, as shown at34a. The key 24 is adapted to be confined within this particular area orsegment of the shifting gear. Thus, by way of example, movement of theshifting gear segment is stopped by the key 24 when one of theteeth 33engages the same or by the stop 34.

As shown in Figure 2, the s1eeve'2l' is carried on the shaft 3 and thehub 31 is confined within the bore l6. Thesleeve 21 bridges theconcavity is and mountedgon said sleeve and within said concavity I9 isa shifting cam 35. The shifting cam is internally screwthreaded at 3Bfor engagement with the screw threads 29 of the sleeve 21.

The shifting cam has two raised segmental cdgecamsurfaces 3! and 38 anda depressed segmental cam surface 39. Separating the cam surfacestl and38 is a transverse groove 40, and lying between an end of'cam surface 31and surface 39 is atransverse groove 4|. The shifting cam is, internallyannularly grooved at 42 to accommodate a coil, spring 43, one end 44 ofwhich projects from a side of the shifting cam. One side of the shiftingcam is provided with a pair of circular flanges 45 and 45 as shown inFigure 14 providing therebetween a diametric way 41 withinwhich wayisreceived the projecting end lugs 48 and 48 of the hub 3!, so that thehub is correctly positioned with respect to the shifting cam. Theopposite-side of the shifting cam is provided with a pair ofspaced-apart arcuate end flanges 5D and 5|, which flanges cooperate withflanges carried by the part known as the low gear lock 52, and whichforms a member of the shifting gear assembly.

Referring to Figure 6, the low gear lock 52 is provided on-one end witha diametric pair of segmental flanges 53 and 54 and with a groove 55adjacent oneend of flange 53,- which groove is adapted to receive theend 44- of the spring 43.

' The low gear lock and the shifting cam are adapted to be in abuttingrelationship, the segmental end flanges 53 and 54 lying adjacent thesegmental flanges 5S and 5|, and in such a manner that said flanges maybe in contact to limit any rotative movement between the shift ing camand the low gear lock in one direction. The low gear lock 52'is providedwith a segmental ratchet tooth portion 56 and with a raised portion 51which functions as a stop. The portion 51 is adapted to have engagementwith the key 24 to limit rotation of the low gear lock in one direction.As shown in Figure 2, both the shifting cam and the low gear lock areconfined within the concavity I9 and are carried upon the shiftingassembly sleeve 21, the arrangement being such that the low gear lock iscapable of rotation upon the sleeve while the shifting cam is locked tothe sleeve by means of the screw threads 29 and 36.

Adapted to surround the shifting cam 35 is mechanism designated as thecam release assembly and illustrated in Figure 13. The cam releaseassembl includes a pair of arcuate shoes 58 and 59, a split annularmember 60 called a keeper and having enlarged or thickened end portionsGI and 62 which are transversely undercut at 63 and 64. A semi-circularmember 65, constituting a spring retainer, is adapted to fit against theperiphery of thekeeper 60 with the ends thereof engaging the undercutportions 63 and 54. The ends of the retainer are reduced in width toprovide shoulders at 66 and 61, and parallel edge flanges are providedat 68.

A pair of rollers 69 and III are received within transverse grooves Hand I2 of the shoes 58 and 59. Each roller is provided with headed endsso as to hold the respective rollers against lateral shifting within thegrooves H and I2. Roller retainers I3 and I4 are provided for sides ofthe shoes, keeper and spring retainer. However, prior to assemblage ofthe roller retainers in position, a coiled tension spring I5 ispositioned so as to surround the shoes and spring retainer asillustrated in Figures 2 and 11. When the roller retainers I3 and I4 arein position, the spring is prevented from escaping from its engagementwith the shoes and spring retainer.

The roller retainers comprise in each instance, plates conforming inoutline to the curvature of the shoes and provided with slots I6 and IIwhich receive the heads of the rollers 89 and I and permit movement ofthe heads within the said slots. These retainers have undercut portionsI8 and I9 which engage the undercut portions 83 and 84 of the keeper,and are received within the shouldered portions 66 and 51 of the springretainer. The roller retainers are held in position by a pin 80 whichpasses between the shoes 58 and 59, see Figure 13. When the cam releaseassembly surrounds the shifting cam 35, the rollers 69 and III will, inthe position shown for the parts in Figure 2, be positioned between thegrooves M and II and 40 and 12, see Fig. 5. In other words, pairs ofthese grooves will be complementarily positioned. The tension spring Iwill hold the rollers within said pairs of grooves and prevent theescape of the rollers therefrom, except upon the occurrence of a suddenimpact force sufficient to cause separation of the shoes under springtension when the shifting cam rotates and positions the rollers on thecam surfaces 31 and 38, as for instance illustrated in Figure 9. Asstated the normal position for the rollers would be that illustrated inFigure 5. I

Assuming an assembly of parts such as illustrated in Figure 11, less thecones8l and 83, the assembly is positioned in sleeve 8 with gear 25 andgear segment teeth 33 engaging teeth I 2, see Figures 2, 3 and 4. Tomaintain this assembly within the sleeve, I have provided the cone 8|which has threaded engagement with threads 22 of the eccentric sleeveshaft and included between the race of the cone and the race II are ballbearings 82. Secured to the threads 2| of the sleeveshaft is the 'cone83.,A race member 84 is positioned adjacent cone 83 with ball bearings85 interposed between said races. 1*

The race member 84 is held in position by an annular case 85, it beingobserved that the race member 84 has a reduced diameter portion whichfits within the confines of one end of the case. The annular case isprovided with internal ratchet teeth 81, which teeth are positionedimmediately adjacent the low gear lock 52,.see Figure 2. Thecase 86 isprovided at one end with an annular race member 88. The construction issuch that when the case is confined within the box 2, one end of the boxwill bear against the external surface of the annular race member. Ballbearings 88 are interposed between the race member and the sleeve'8.

A cap 98 is in threaded engagement with the case at 3| which cap bearsagainst the opposite end of the box, and thereby secures the caseagainst lateral shifting within the box; Thus, the parts when assembled,have the relationship shown in Figure 2. They diameter of the case issuch as to fit within the crank hanger box of conventional size, and asthe transmission is fully assembled, all thatneed be done is to screwthe cap 98 onto the threads of the case and against the opposite end ofthe box to correctly position the transmission therein. Thereafter,crank arms 4 and 5 are securedto ends of the shaft 3.

Figure 12 shows the case, the left bearing cone 84, and the cap 98. Thesleeve 8 to the left of the showing of Figure 12 fits within the case.Various locking arrangements may be resorted to for the left and rightcones, as for instance,

illustrated for the right cone, at 92. In the practice of the invention,I provide needle bearings between the shaft 3 and the eccentric sleeveshaft, as shown at 93 and94. To properly stabilize the structure, I havepro.- vided a bronze bearing 95 which surrounds portion 26 of theeccentric sleeve shaft and is in engagement with the portion I3 of thesleeve 8.

The operation, uses and advantages of the in vention just described, areas follows:

Assuming the parts in position, as illustrated in Figures 1 and 2, withthe sprocketupon the right side of the bicycle frame, looking toward thehandle bars; that is, forwardly, the direction of rotation of thesprocket I to propel the bicycle forwardly will be that indicated by thearrows adjacent the cranks 4 and 5, in other words, clockwise rotation.In this position of the parts, the teeth of the gear 25 and the teeth 33of the shifting gear segment 30 engage the teeth I2 of the sleeve 8.Thus, as the shaft 3 is rotated, rotation is communicated directlythrough the gears 25 and I2 to produce direct rotation of the sleeve 8and of the sprocket I with gear segment 30 serving to prevent eccentricaction of the sleeve shaft I4. In other words,.there is a lockedrelationship between the gears. This locked' relationship is illustratedin Figures 3 and 4.

In this locked relationship, the rollers 69 and III are between thegrooves II and I2 of the shoes 58 and 59, and the grooves 48 and M ofthe shifting cam 35. All of these members will,

therefore, rotate with rotation of the shaft 3 i and of the eccentricsleeve shaft I4; As the shaft 3 is eccentric within the sleeve shaft'l4,such rotation will produce a slight'eccentricity in the pedaling.Experience has taught, however, that this slight eccentricity ofrotation is hardly noticeable to the bicycle rider.: s

During this pedaling, the stop 34 of the shiftlDQTEEaI' 'SBEBIBIIt 30 isin engagement with the key:24-,. seeFigure-4. Furthermore, the stop: 51ofthe lowgear lock engages the samelrey 24. In thispositionthe ratchetteeth of the low gear lock are free of engagement from the ratchet teeth8'! of the non-rotatable case 86.

- It: will be observed that the, shifting assembly shown iii-Figure i4is freely'carried upon the shaft il. The cam releaseassembly of Figure13 cooperates with the shifting cam of the shifting assembly of Fig. 14in the manner shown in Figure 2. The eccentricsleeve shaft of Figure 15,which is formed with eccentric semi-circular concavitieslfl and I8,providesshoulders at 19c and e912, and the roller retainers l3 and 14and the arcuate shoes 58 and 59 bridge the shoulders (s'ee'Fig. 5) insuch a manner that rotationiof the" eccentric sleeve shaft producessimultaneous turning movement of-the cam release assembly.

While pedaling in high gear, the teeth 33 and the teeth'of gear 25 arein the position shown in Figure 11, and both engage the gear l2. As aconsequence, the completed assembly shown in Figure 11 rotates, as doeslikewise the sleeve 8 within the non-rotatable case 86.

Therefore, in high gear, the drive shaft 3, the sleeveshaft M and thegear l2 along with their component parts, rotate as a locked assembly.When in second speed; the sleeve shaft 14 is locked in a stationaryposition and the rotating 'driveshaft pinion gear 25 drives the gear 12at a reduced speed. The automatic shifting assembly consistsoi: a gearsegment 393;v a cam 35; release rollers 69 and Ill and shoes 58 and 55which are incorporated in a torque measuring device (Fig. 13); a lowgear lock 52 and nonrotatable ratchet-type teeth 81 which are attached.to the case 86. When pedaling in high gear both the sleeve shaft ['4 andthe gear ii are rotating as a locked assembly. Note that thedrive shaftand all'members of the shifting assembly (with the exception of thenon-rotatable: ratchet teeth) are being carried with the sleeveshaft andtravel in an orbit around the axis of the sleeve shaft, in a mannersimilar to planetary gears when locked to asun gear, with the exceptionthat the driving force is applied to the planetary gear equivalent.Therefore, the

direction of forces (when viewed from the :2;

sprocket side with the bicycle being propelled forward) is such that thedrive shaft 3 attempts torotate clockwise about its'planetary axis andthat'the drive shaft axis attempts to travel in its orbitcounterclockwise about the sun axis of and 12 in the release shoes,which bear against the sleeve shaft. Therefore, the drive'shaft 3 merelyfunctions as attachment points for the cranks 4. and 5 and the drivingforce is transmitted, by lever-action, tocause rotation of the entireassembly about the common axis of the sleeve shaft [4- and gear 1-2 in aclockwise direction. As the torque on the drive shaft is increased, thecounter for'ces, resulting from the engagement of the pinion gear 25 andthe gear 1'2; increase with the result that the drive shaft 3 seeks totravel its planetary orbit in an opposite direction to the rotation ofgear [2. The

forces exerted along the planetary orbit are transmitted through thegear segmentiill to the cam 35 which attempts to rotate and which inturn attempts to force the rollers 69 and 10 out of grooves 40 and 4| inthe cam. A coiled tension spring 15, which functions as a torquemeasuring device holds the rollers in their respective grooves. If theforces transmitted to the cam are sufficient to overcome the tension ofthis spring, thecam 35 and gear segment 30 will rotate on the planetaryaxis and the teeth 33 of the gear segment 30 will move in eccentricrelation to the gear teeth l2 until they are no longer in engagement-Coupledto the cam 35 and gear segment 30, by means of a coil couplingspring 43, and on the same planetary axis, is a low gear lock 52 whichis rotated in an eccentric relation to thesleeve shaft and movesintopositlon to mesh with the non-rotatable ratchet teethx8l', thuslocking the sleeve shaft to the casex86. The release shoes 58 and 59'are employed to increase inertia which must be overcome before shiftingtakes place, with the result that sudden shock forces applied to thedrive shaft are more effective than a gradual increase of torque. Thecoil spring 4-3 between the cam 35- and low gear lock 52 serves tofacilitate alignment regardless of the position in the planetary orbitat the time shifting occurs.

If low gear is desired, a sudden impact upon one of the pedals 6 in thedirection of the arrows of Figure 1 will cause a shifting of the gearsso that the rear wheel is now driven by gear 25, rotating the gear l2.As long as the teeth 33 and the teeth of gear are in alignment, as shownin Figure 11, with-both engaging gear 12, the gear 25- cannot rotate.However, when sudden impact is made onthe pedals, a portion of theimpact force is transmitted through the gear segment to the cam forcingrollers 69 and '10 from grooves 4i) and 4|. The gear segment 3flthenfunctions as a gear to rotate the cam 35 into position shown in Figure9, whereupon the teeth-56 of the low gear lock 52 engage the ratchetteeth 8-! to complete the rotation of gear segment 30 and thuscompletely release teeth 33 from engagement with gear 1-2.

The dot X and the dot Y represent the center of rotation of theeccentric shaft 3 and the cocentric sleeve shaft M, respectively. Thedistance between these shafts is the amount of cocentricity of theeccentric shaft 3 with respect to the eccentric sleeve shaft l4.

Referring to Figure" 3, the turning effort to drive gear 25' is in thedirection of the arrow It is tobe remembered that gear 25' is eccentricto the axis of the internal gear l2. There is, therefore, a slight leverarm due tothe difference bet'weenthe axes and the tendency of thecocentric sleeve shaft I4 is torotate in the direction of the arrow 1),which is directly opposite to the directionof rotation of gear 25. Inother words, the gear 25, assuming. gear 12 is stationary, attempts toclimb around the teethof said gear. and this attempt to climb imposes arotation upon the eccentric sleeve shaft. 7

As the eccentric sleeve shaft is rotated in the direction of the arrowb; the shoes 58' and 59-, well as the roller retainer members 13 and M,will turn with the eccentric sleeve shaft for the reason that thesemembers are: in direct contact with the shoulder portions lilo; and I92)ofsaid eccentric" sleeveshaft. As the teeth 33 of the shifting gearsegment are still in engagement with the teeth [-2, as shown in Figure4, the

rollers 69 and 10 will then leave the grooves 40 and 4| and be receivedupon the cam surfaces 31 and 38 of the shifting cam (see Fig. 9), itbeing remembered that the shifting assembly of Figure 14 are allinterconnected for simultaneous rotation.

The direction of movement of the shifting gear segment is in accordancewith the arrow (Fig. 4), and as the direction of movement of theeccentric sleeve shaft is in accordance with the arrow 5 (Fig. 4) due toeccentricity between the axis of gear l2 and the eccentric sleeve shaftl4, the teeth 33 will leave the gear teeth 12 in the manner shown inFigure 8. In so leaving, the ratchet teeth of the low gear lock arebrought into engagement with the ratchet teeth 81 of the non-rotatablecase 86. This engagement prevents any further counterclockwise rotationof the eccentric sleeve shaft I4. It is obvious that when this occurs,gear will rotate the ear l2. g

If now it is desired to return to high gear, a reverse pressure is madeupon the pedals in a direction opposite to that of the arrows ofFigure 1. This reversed pressure will restore the shifting gear to theposition shown in Fi ure 11. To accomplish this, assume that the partsare not in movement, and referring to Figures 7 to 10, reversed pressureon the pedals will cause gear 25 to follow the internal gear l2 byrotating in a counterclockwise direction with respect to the center X,as indicated by the arrow d in Fig. '7. The eccentric sleeve shaft 14will rotate in a clockwise direction about the center Y of the gear I2,as indicated by the arrow e of Fig. '7.

As the shaft 3 rotates about the center Y, the low gear lock 52 will berotated counterclockwise about the center X, because of the contact ofthe teeth 56 with the teeth 81. Due to the fact that the low gear lock-52 is resiliently conk ,.cam and the low gear lock 52 through itsprojecting end 44, which is received in the slot 55 in the low gearlocl; 52. As the teeth 33 enage gear l2, as illustrated in Figure 3, therollers 69 and 10 drop into depressions and 4|, and the shoes 58 and 59are forced inwardly by the spring 15, thus locking the shifting gearassembly in the high gear position shown in Fig. 11.

It is pointed out that shifting from high to low gear is under controlof the cam release assembly. The spring 15 of this assembly may have itstension varied so as to require greater or lesser impact upon the pedalsto cause movement thereof relative to cam 35. The cam release assembly,however, does not control the shifting from low gear to high gear, asthe shoes 53 and 59 are expanded radially and are not in contact withshoulders l9a and l9b of the eccentric sleeve shaft l4, see Fig. 9.

It will be seen that I have provided a simple device of few parts, whichis under the direct pedaling control of the bicycle rider to provide anautomatic transmission having a variable speed control as to shifting bya sudden impact upon the pedals in one of two directions. A.

forward impact in the direction of movement of the bicycle shifting to alow gear, and a slight back movement on the pedals reshifting into highgear. 2

It is obvious that the invention may be used on power ormanual drivenmechanisms, other than bicycles.

I claim: 1. In a device of the character disclosed, a drive shaft, asleeve shaft eccentrically carried on said drive shaft, said sleeveshaft provided with two spaced concavities, a drive gear mounted on thedrive shaft and positioned within one of said concavities, a segmentalgear mounted on the drive shaft and positioned in the, same concavitywith the drive gear, an annular cam mounted upon the drive shaft andpositioned,

of the sleeve shaft with the teeth thereof in engagement with the teethof the drive gear and the segmental gear, cam rollers engaging theannular cam, and means surrounding the sleeve shaft in the zone of thesecond concavity for maintaining said cam rollers in engagement with theannular cam.

2. In a device of the character disclosed, a drive shaft, a sleeve shafteccentrically carried on said'drive shaft, said sleeve shaft providedwith two spaced concavities, a drive gear mounted on the drive shaft andpositioned withinone of said concavities, a segmental gear mounted onthe drive shaft and positioned in the same concavity with the drivegear, an annular cam mounted upon the drive shaft and positioned withinthe second concavity, said annular cam ,being secured to the segmentalgear whereby movement of said gear produces movement of the annular cam,a sleeve provided with internal gear teeth overlying the first concavityof the sleeve shaft with the teeth thereof in engagement with-the teethof the drive gear and the segmental gear, cam rollers engaging the an--nular cam, means surrounding the sleeve shaft in the zone of the secondconcavity for maintaining said cam roller in engagement with the annularcam, a non-rotatable annular case enclosing the sleeve provided with aninternal gear and the sleeve shaft, said non-rotatable case providedwith an annular series of internal ratchet teeth, and a segmentalratchet tooth member yieldingly secured to said annular cam andpositioned in the second concavity of the sleeve shaft in position toengage the internal teeth of the case when the segmental toothed memberis rotated in one direction.

3. An automatic transmission including a drive shaft, a drive gearcarried thereby, a ring gear surrounding the drive gear and in meshtherewith, the axis of the drive gear being eccentric to the axis of thering gear, a sleeve shaft'eccentrically mounted on the drive shaft, acam loosely carried on the drive shaft, a segmental gear carried by thedrive shaft and adapted to mesh with the teeth of the ring gear, thering gear teeth and the segmental gear teeth having the same pitchdiameter, the axis of the segmental gear being in eccentric relation tothe normal segmental gear center, and a means carried by the sleeveshaft and movable therewith for holding the cam to prevent rotation ofthe segmental 1, a a d up n app c io of a dit onal th to release the camand permit rotation of the segmental gear to disengage the segmentalgear from tooth engagement with the ring gear.

'4. An automatic'transmission, including a drive shaft, a sleeve shafteccentricallymounted on'the drive shaft, a drive gear fixedly securedtothe drive shaft, a driven gear in mesh with said drive gear, a segmentalshifting gear and a cam secured thereto, both loosely carried on thedrive shaft, and normally in'mesh 'with the teeth of the driven gear,means normallypreventing rotation of the cam to prevent rotation of thesegmental shifting gear, sudden impact-in one of two directions on thedrive gear releasing the means for normally preventing rotation of thedam to release said cam and allow counter-rotation of the sleeve shaftrelative to the turning direction of the drive gear, to rotate thesegmental shifting gea-r'from engagement with the teeth of drive gear. r

'5. An automatic transmission 'i-ncludinga drive shaft, asleeve shafteccentrically-mounted on'the drive shaft, a drive gear fixedly securedto the drive shaft, a sleeve provided with internal gear teeth enclosinga part of the eccentric sleeve shaft, with the teeth of the drive gearin driving relationship with the teeth of the sleeve; means associatedwith the sleeve adapted to be driven when the sleeve is rotated, asegmental shifting gear carried by the drive shaft and adapted to meshwith the teeth of the sleeve, a:cam -loosely carried on the drive shaftand fixedly .connected to the segmental shifting gear, means to lock-thecam to the sleeve. shaft, to in turn lock the segmental shifting gear inmesh with the teethiof the .sleeve to "prevent relative gear rotation.

.6. An automatic transmission including a drive shaft to whichpedal armsare attached, asleeve shaft .eccentrieally mounted upon the drive shaft,a ring gear surrounding the sleeve shaft, .a drive gear fixedly carriedby the drive shaft and eneas n th te t o he n gear. a member carried onthe drive shaft and. provided with a segmental gear for engagement withthe teeth as Number of the ring ear, an annular. cam secured-to -sa:id

12 last named member, and means for locking the cam to the sleeve shaftto lock the segmental gear in mesh with the ring gear and therebyprevent relative gear rotation, sudden impact releasing the cam topermit the segmental gear to disengage the ring gear.

,7. In a device of the character disclosed, a drive shaft,'a sleeveshafteccentrical'ly carried 'on'said drive shaft, said sleeve shaftprovidedwithtwo spaced concavities, a drivegear mounted .on the driveshaft and positioned in one of said concavities, a segmental gearmounted on the drive shaft and positioned in the same concavity with thedrive gear, an annular cam"mounted'npon the drive shaft and positionedwithin the second concavity, said annular cam being secured'to thesegmental gear whereby-movement ofsaid gear produces movementof {theannular jcam, asleeve provided with internal gear-teeth overlying thefirst concavity of the sleeve shaft, -with"-the"teeth thereof inengagement with the teeth of the'drive gear and the segmental gear, camrollers engaging the annular cam to-lock the-segmental gear in mesh withthe ring gear so that-thegears'cannot rotate relative to each other,means surrounding the sle'eve' shaft in the'zone of theisec- 0ndconcavity for maintaining said cam rollers in engagement with theannularcam and means to rotate the segmental gear to a position re- Ileasing the ring gear "from locked engagement therewith. I

WIBLIAMG. SPENCER.

REFERENCES erren The following references are of more in "the file ofthis patent:

UNITED STA ES PATENTS Number Name Date Weber 1,757,995 Fawiek r Mia-v13,1930 2,447,136 Putz Aug.'1'7 19'48 FOREIGN PATENTS Gountry. Date 92,574

Germany June '11, 1,896

